1. Field of the Invention
The present invention relates to an external flash device for a camera, in particular, to an external flash device which is mounted for use on a mounting seat of a camera provided with an internal flash device.
2. Description of the Related Art
Generally, photographing using an electric flash device has a drawback that it gives an unnatural picture without shadows because the electric flash device mounted on a camera illuminates the subject from a position in front of it.
Conventionally, for resolving the above problem, a bounce lighting using a so-called two-lamp flash is known as disclosed in Japanese Unexamined Patent Application Publication No. Sho 58-113919, Japanese Examined Patent Application Publication No. Sho 59-47440, and so forth, in which a two-lamp flash device is used, that is, a main luminescent unit having a larger light amount illuminates a ceiling, the reflected light from which mainly illuminates a subject from above, while the other sub-luminescent unit having a smaller light amount directly illuminates the subject.
When this method is used, the bounce light makes natural shadows in the lower area and the direct illumination light from the sub-luminescent unit adequately illuminates the shadow area where gradation is lost. Therefore, the method is effective especially for portrait photographing because natural shadows are made and catchlights are made in the eyes of a person by the direct illumination.
There is another conventional problem that, when a close-up photographing is carried out with a flash device mounted on a camera, the subject is illuminated by an insufficient amount of light and the lighting causes an uneven illumination because of a parallax between a photographing lens and a light emitting window of the flash device.
Conventionally, methods for resolving such problems described above are disclosed in Japanese Unexamined Patent Application Publication Nos. Sho 57-122423, and Hei 9-15689 which was previously filed by the inventor of the present invention, and so forth.
However, providing two luminescent units for a flash device, as disclosed in Japanese Unexamined Patent Application Publication No. Sho 58-113919, Japanese Examined Patent Application Publication No. Sho 59-47440, and so forth, has a problem that the flash device becomes large and expensive.
Moreover, since it is not that a natural lighting is obtained by simply illuminating the subject with a bounce light and a direct light from in front of the subject, an additional change is added to reduce the direct front illumination relatively to the bounce light as shown in, for example, Japanese Examined Patent Application Publication No. Sho 59-47440 in which the direct front illumination is effectively reduced by delaying the start of the emission.
The flash device disclosed in Japanese Unexamined Patent Application Publication No. Sho 57-122423 is a flash device which automatically adjusts the luminescent unit thereof to the optical axis according to a shooting distance, but it has a problem that it requires the camera and the photographing lens having a distance measuring function, and therefore the method is not useable for a camera which does not have the function.
Furthermore, in a case of the close-up photographing at an extremely short distance, if a subject is illuminated by the light from the flash device without dimming, a problem frequently occurs that too large an F-value (too small aperture stop), which is not provided for the photographing lens, is required for the lens to obtain an appropriate exposure.
On the other hand, in a flash device disclosed in Japanese Unexamined Patent Application Publication No. Hei 9-15689, since a method is provided to dim the light from the flash device for the close-up photographing, the problem, that too large an F-value is required which is not available with the photographing lens, does not occur.
However, the flash device disclosed in the patent laid-open is only realized by a flash device whose luminescent unit can rotate horizontally around its leg part inserted and fixed in the camera, and it has such problems that its mechanism is complicated requiring many parts and that the operation is not simple because it accommodates a folded dimming plate (diffusion plate).
It is an object of the present invention to carry out a two-lamp-lighting photographing easily and reliably, in which the light from an external flash device is used as a main light source and the light from an internal flash device of a camera is used as a supplementary light source.
According to one embodiment of the present invention, a dimming plate for dimming the light from the internal flash device of the camera is disposed on the external flash device which is mounted for use on the mounting seat of the camera. The light from the internal flash device of the camera is dimmed by covering a luminescent unit of the internal flash device of the camera with the dimming plate of the external flash device in order to perform two-lamp-lighting photographing. This enables simple, reliable two-lamp-lighting photographing in which the light emission from the external flash device is a main light source and the light emission from the internal flash device of the camera is a supplementary light source. Further, the external flash device can be provided at inexpensive price because only incorporating the dimming plate therein realizes the two-lamp-lighting photographing without disposing a special supplementary luminescent unit on the external flash device.
According to another embodiment of the present invention, the external flash device has a mounting unit to be mounted on the mounting seat of a camera provided with an internal flash device, a body unit connected with the mounting unit, a luminescent unit connected with the body unit and a dimming plate which is disposed on the body unit and can dim the light of the internal flash device. Then, a two-lamp-lighting photographing is carried out in a state where the light emitted from the internal flash device of the camera is dimmed by covering the luminescent unit of the internal flash device of the camera with the dimming plate disposed on the body unit of the external flash device. This enables easy, reliable two-lamp-lighting photographing where the light emission from the external flash device is used as a main light source and the light emission from the internal flash device of the camera as a supplementary light source. Further, the external flash device can be provided at an inexpensive price because only incorporating the dimming plate in the body unit of the external flash device realizes the two-lamp-lighting photographing.
According to another embodiment of the present invention, the internal flash device of the camera is disposed so as to be able to pop up and the external flash device is mounted on the mounting seat of the camera. The body unit is disposed so as not to get in contact with the internal flash device when the internal flash device pops up from the camera. The internal flash device of the camera is popped up for use, for example, from the top of the camera when the internal flash device is ready to emit light.
The popped-up internal flash device is surely prevented from hitting the external flash device since the body unit of the external flash device is disposed so as not to get in contact with the internal flash device when the internal flash device is ready to emit light.
According to yet another embodiment of the present invention, the dimming plate of the external flash device is disposed at a position changeable relative to the body unit. For example, the dimming plate is pivotally disposed relative to the body unit so that its position is readily and reliably changeable. In this way, the dimming plate can be disposed at a proper predetermined position easily and reliably.
According to yet another embodiment of the present invention, a supporting member is disposed on the body unit of the external flash device in a manner that it can be accommodated in the body unit, and a dimmer plate is disposed at one end of the supporting member. Therefore, the front of the luminescent unit of the external flash device itself can be covered with the dimming plate by, for example, pulling out the supporting member from the body unit.
In yet another embodiment of the present invention, the dimming plate of the external flash device selects either the luminescent unit or the internal flash device and can move to the front of the luminescent unit or of the internal flash device. A two-lamp-lighting photographing is carried out with the dimming plate positioned in front of the internal flash device, by using the light emission from the external flash device as a main light source and the light emission from the internal flash device of the camera as a supplementary light source. Further, the dimming plate is positioned in front of the luminescent unit of the external flash device to carry out a close-up photographing in which its light intensity is reduced by using only the external flash device. In this way, a close-up photographing in which only the external flash device is used is carried out with easiness and sureness as well as the two-lamp-lighting photographing.
According to yet another embodiment of the present invention, the external flash device has a detecting device for detecting the pop-up of the internal flash device. Therefore, it can detect the pop-up of the internal flash device reliably.
According to yet another embodiment of the present invention, the external flash device has a displaying device which indicates that the internal flash device is in a pop-up state when the detecting device detects the pop-up of the internal flash device. Therefore, by looking at the displaying device, it is possible for users to know easily and reliably that the internal flash device is in the pop-up state. Further, by displaying on the display device whether or not the external flash device is attached to the camera, it is possible to easily and reliably tell users that the camera is in the two-lamp-photographing mode.
According to yet another embodiment of the present invention, the external flash device has a slave device which enables detection of light emission from the internal flash device when the detecting device detects the pop-up of the internal flash device. Therefore, it becomes possible to have the external flash device emit light reliably following the light emission from the internal flash device, so that the two-lamp-lighting photographing can be carried out reliably.
According to yet another embodiment of the present invention, the external flash device has a slave device which detects light emission from the internal flash device or other flash devices. The slave device sets the slave sensitivity at a lower level when the external flash device is mounted on the mounting seat of the camera than when the external flash device is not mounted. In this way, the slave sensitivity is low while the external flash device is mounted on the mounting seat of the camera so that the external flash device is able to reliably emit light following not light emission from other flash devices but only the light emission from the internal flash device. The slave sensitivity is high while the external flash device is not mounted on the mounting seat of the camera so the external flash device can emit light following light emission from a built-in flash device at a distance.
According to yet another embodiment of the present invention, the external flash device has a control member which is controlled to enable or disable slave emission when the external flash device is not mounted on the mounting seat of the camera. By holding the external flash device, for example, with his hand, a photographer can control the control member to enable the slave emission at his own photographing timing when the external flash device is not mounted on the mounting seat of the camera. Therefore, it is possible to surely emit light from the external flash device following not light emission from flash devices of other photographers but only the light emission of the internal flash device.